Breechblock device for firearms



Oct. 18, 1949. J, KOUCKY BREECHBLOCK DEVICE FOR FIREARMS Filed July 24,1947 A \m\\\ w;; N

INVEN & 1W4;

BY KW P Ahmad Patented Oct. 18, 1949 BREECHBLOCK DEVICE FOR FIREARMSJosef Kouck-y, Prague, Czechoslovakia, assignor t Zbrojovka Brno,Narodni Podnik (also named Brno Arms Factory, National corpora tion),Prague, Czechoslovakia, a corporationof Czechoslovakia Application July24, 1947, Serial No. 763,363 In Germany December 11, 1943 2 Claims.

My invention relates to a breechblock device for firearms and is afurther improvement of the device disclosed in my prior Patent No.2,356,595.

The essential part of said device is a breechblock slidably and tiltablymounted in the casing, said breechblock having locking lugs which intilted position engage corresponding recesses in the casing. In theolder device the length of the tiltable breechblock has to exceed thelength of the cartridge chamber opening through which cartridges areintroduced into the firing position to leave a sufliciently long part ofthe breech block supported in the casing during the tilting movementeffecting the locking and unlocking of the breechblock. The breechblock,therefore, has to have a greater length than necessary for its safeguidance during its sliding movements, and this greater length results,of course, in an increase in weight of said breechblock. This is ofdisadvantage especially when the breechblock device is used ingas-operated firearms wherein the masses of moving parts and the lengthand weight of the casing have to be kept as small as possible.

The main object of my invention is to overcome the above mentioneddifficulties. According to my invention the breechblock is divided intwo component parts; namely, a slide member guided in the casing and infront thereof and coupled thereto a rotatable bolt member having lockinglugs engaging corresponding recesses in the casing or in the breech.Such construction contrives not only to reduce the Weight and length ofthe firearms, but also to enhance its stability as the center of gravityis moved backwards, that is away from the barrel.

The said and other objects of my invention will be more fully understoodfrom the following specification taken with the accompanying drawing inwhich one embodiment thereof is illustrated.

In the drawing Fig. 1 illustrates schematically in a side view, partlyin section, the arrangement of the breechblock within the casing,

Fig. 2 shows a horizontal section through the breechblock along the line2--2 in Fig. 3.

Fig. 3 shows an end view of the breechblock in the direction of arrow 3in Fig. 2 and shows also part of the casing in section, and

Fig. 4 shows a perspective view of the breechblock.

The breechblock has an essentially prismatic shape and is composed oftwo adjoining and cooperating parts namely a slide member I I and a boltmember i2 in part thereof.

Each of these parts H and I2 has a pair of laterally arranged shouldersI3 which move in corresponding slide channels i6 arranged in the casingIS. The front end of the breechblock part 12 is provided with a pair oftriangular locking lugs 23 as disclosed in my Patent No. 2,356,595.These known locking lugs 23' are formed at the end of the beveled faces22 which are arranged in the bottom and top face of the bolt member I 2.The said lockin lugs 23 engage corresponding recesses I! in the casingI5 or in the breech of the barrel after the bolt member H has beenturned into locking position. This turning of the bolt member [2 iseffected with the help of the inclined groove 25 arranged laterallythereon into which engages in a manner known per se an active member ofan operating handle for moving the breechblock back and forth, or anactive member of the gas cylinder group to eiiect the breechblockmovement automatically.

The bolt member I 2 is provided with a pivot I 8 which extends into andseats in a corresponding axial bore arranged in the slide member II. Thebase of said bore is extended into an annular groove i 9 (Fig. 2) intowhich lead two longitudinal grooves 20 arranged in diametrically opposedpositions in the top and in the base respectively of said bore (Fig. 3).The pivot I8 is provided at its outer end with two opposing radial teeth2| which are introduced through said longitudinal grooves 20 until theyengage the annular groove l9 so that the forepart l2 may be turned byinto the locking position shown in Figs. 2 and 3.

The bolt member I2 is provided on its front end with two locking lugs 23which are formed by chamfered surfaces 22 in the same way as describedin my Patent No. 2,365,595. These lugs 23 after slightly turning thebolt l2 engage corresponding recesses I! in the casing i5. This turningis achieved with the help of the inclined groove 25 into which engagesan active member of the breechblock displacing device as stated above.

The bolt member 12 is further provided with a longitudinal boring intowhich the ejector 28 is introduced and held therein by a compressionspring 29 resting with its other end upon a pin 30 slidingly arranged insaid boring. The free end of said pin 30 is pressed against and slidesupon the front face of the slide member II and rests in a recess 3| thussecuring the breechblock parts H and 12 in their relative position shownin Figs. 2 and 4.

The breechblock parts II and ['2 contain the striker 32 which is chargedwith the spring 33. The bolt member l2 contains also a conventionalcartridge extractor 34.

Although I have shown and described a specific embodiment of myinvention, it will be apparent to those skilled in the art that manychanges, substitutions, additions and omissions may be made thereinwithout departing from the spirit of my invention as set forth in theappended claims. Thus the shape of the two breechblock parts, as well asthe connecting and securing means used to join the said partsmay be ofdifferent construction.

What I claim as my invention is:

1. In a breechblock device for firearms, a casing, a breechblockslidably mounted in said casing, said breechblock comprising a slidemember guided in said casing and a bolt member adjoining said slidemember in front thereof, a pivot upon said bolt member extending axiallyinto said slide member and a corresponding boring in the latter torotatably support said pivot, a circular groove arranged at the base ofsaid boring, at least one tooth upon said pivot interlocking with saidcircular groove, an axially extending groove in said boring for each ofsaid teeth to permit the same to pass into said circular groove, lockinglugs arranged on said bolt member and recesses in said casing adapted toreceive said lugs, and means for turning said bolt member from anunlocked position to a locked position in which said lugs are receivedin said recesses.

2. In a breechblock' device for firearms, a casing, a breechblockslidably mounted in said casing, said breechblock comprising a slidemember guided in said casing and a bolt member rotatably coupled theretoin permanently adjoining position in front thereof, coupling meanspermitting a rotation of said bolt member with regard to said slidemember, locking lugs arranged on said bolt member and recesses in saidcasing adapted to receive said lugs, means for turning said bolt memberfrom an unlocked position to a locked position in which said lugs arereceived in said recesses, a boring in the bolt member, an ejector inthe front part of said boring, a locking pin in its rear part, apressure spring between said ejector and said locking pin, and a recessin the front face of the slide member cooperating with said locking pin.

J OSEF KOUCKY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,096,324 Stamm May 12, 19141,228,827 Saalfield June 5, 1917 2,035,539 Dicke Mar. 31, 1936 2,125,571Jacobson Aug. 2, 1938 2,424,264 Yorks July 22, 1947

